Ms Grunt's Class Resources:
Science behind Color Theory
Penn Wood High School
Simultaneous Contrast
The way we perceive color (and value) is influenced by the color (and value) surrounding it. Note how this sphere appears. Is it the same value or is there a shift in value from top to bottom?
Most see a lighter top and darker bottom. In fact, the entire sphere is the same shade of grey (seen below), but due to the shift in value in the background, our eye perceives the circle to shift.
Look carefully at the two grey lines below. One overlaps black lines, the other overlaps white lines. They appear to be two different shades of grey. However, for the same reason that the circle appears to shift, these grey lines are influenced by the values surrounding them, making them appear to be different when in fact they are the same value.
SOURCE:
The Secret Language of Color,
By Joan Eckstut and Arielle Eckstut
This is an excellent book and I highly recommend it!
Next, click on the link below for an interactive demonstration of simultaneous contrast: